This invention relates to a depthometer for underwater diving.
In particular, the invention relates to a depthometer of the type comprising a substantially cup-shaped casing closed at its front by a cover or front glass window which is also substantially cup-shaped and is snap-coupled in a rotatable manner to the end of a side wall of the casing.
In general, in depthometers of the aforesaid type, water is prevented from entering the casing by a seal gasket disposed in contact with the outer lateral surface of the casing and cooperating with an inner lateral surface of the cover.
Because of the presence of said seal gasket, it is generally difficult to snap-mount the cover on to the casing because air is prevented from escaping from the casing as the cover becomes mounted thereon, so generating therein an overpressure which prevents the cover sliding axially relative to the casing.
In order to prevent this drawback, it is known to provide through the cover a bore which after assembly is closed by means of a screw or a similar removable device.
This solution to the problem has proved not without drawbacks, in that said bore represents a weakening of the casing cover, and the screw can be accidentally disturbed by the user, with the consequence that water enters the instrument.